The overall goal of this Program Project is to understand the clinical, cellular and molecular mechanisms that underlie arterial dysfunction, with a focus on the pathobiology of diabetic vasculopathy. This application is for the renewal of a Program Project Grant that has been funded continuously for 12 years. In this renewal application, as in the current Program, we propose a broad range of experimental approaches that range from molecular analyses to studies of human patients. Project 1 is entitled "Insulin and receptor-modulated pathways of eNOS regulation" and is led by the Principal Investigator of this Program, Dr. Thomas Michel. The proposed studies build upon recent discoveries in Dr. Michel's laboratory on the insulin-modulated reversible nitrosation of eNOS and on recent findings on the differential roles of caveolin in insulin signaling. Project 2 is entitled "KLF2, diabetes, and gene regulation in endothelial cells", and is led by Dr. Mukesh Jain, whose recent discoveries on the central role of the transcription factor KLF2 have provided important new insights into the coordinated control of endothelial gene expression in normal and diabetic states. Dr. Richard Lee leads Project 3, "Thioredoxin and control of vascular redox state" explores the role of the newly-identified glucose-regulated protein Txnip (thioredoxin-interacting protein) in the regulation of the key redoxactive protein thioredoxin in vascular tissues. Dr. Jorge Plutzky's Project 4, "Modulation of endogenous PPAR activation" extends his group's prior observations regarding endogenous PPAR ligands to explore his novel findings on endogenous pathways of PPAR antagonism. Project 5, led by Dr. Mark Creager, is entitled "Mechanisms of arterial dysfunction in patients with type 2 diabetes mellitus" and will explore in these patients the role of insulin modulated nitric oxide signaling pathways in the control of vascular function, with a focus on the effects of free fatty acids, the mechanisms of insulin resistance, and the role of inflammation. An Administrative Core A (Dr. Michel) will provide budgetary, logistic and administrative support for the project leaders in this Program. Core B (Drs. Brian Hoffman and George King), "Animal models of diabetes and arterial dysfunction" will provide support for the development and analysis of animal models relevant to study of diabetic arteriopathy. Core C (Dr. Peter Libby), "Tissue Analyses", will perform immunohistochemical and lipid analyses. All the investigators in this Program have had longstanding scientific interactions, and together propose a broad range of complementary and synergistic experimental approaches to a fundamental problem in vascular disease.